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排序方式: 共有464条查询结果,搜索用时 218 毫秒
351.
Masahiro Takatani Osamu Kato Takashi Kitayama Tadashi Okamoto Mitsuhiko Tanahashi 《Journal of Wood Science》2000,46(3):210-214
The effect of steam-exploded wood flour (SE) added to wood flour/plastic composite was examined using SE from beech, Japanese cedar, and red meranti and three kinds of thermoplastic polymer: polymethylmethacrylate, polyvinyl chloride, and polystyrene. Addition of SE increased the fracture strength and water resistance of the composite board to an extent dependent on the polymer species and the composition of wood/SE/polymer. However, water resistance decreased with the increasing proportion of SE when SE meranti was added. Effects of the wood species of SE on the properties of resulting board were small. An increased moisture content of wood flour or SE (or both) increased the variation of board performance. 相似文献
352.
By T. Oikawa K. Sato S. Takahashi 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1999,116(6):467-473
The inbreeding coefficient (F) is used as a central parameter inferring a proportion of alleles identical by descent within an individual and by genetic variability within a population. The actual inbreeding coefficient varies around a central value, the inbreeding coefficient. C ockerham and W eir (1983) derived the method for computing the variance of inbreeding while reviewing several other methods. The variance of inbreeding in their report was considered to be of two components: one within population and the other between population of varied pedigrees. If pedigree is fixed, F is easily computed for an individual by the standard method (F alconer 1989). For domestic animals, pedigree information is usually available because it is requisite for a programme of genetic improvement. In this study, the variance of inbreeding coefficient was derived for an individual with a pedigree having a single path to a foundation animal. 相似文献
353.
Ali Awaludin Takuro Hirai Toshiro Hayashikawa Yoshihisa Sasaki Akio Oikawa 《Journal of Wood Science》2008,54(2):114-120
The adoption of a concept similar to the prestressing technique used in laminated wood decks of bridge structures might increase
the initial stiffness or ultimate resistance of dowel-type timber joints by applying pretension to their bolts. This study
investigated the effect of pretension in bolts on hysteretic responses and ultimate properties of moment-carrying timber joints
with steel side plates. A pretension of 20 kN that yielded a prestress level of 1600 kPa or about 90% of the allowable long-term
end-bearing strength of spruce species was applied to the bolts of prestressed joints. The superiority of the prestressed
joint over the non-pre-stressed joint was proved by very high hysteretic damping, equivalent viscous damping ratio, and cyclic
stiffness. At any given rotation level, hysteretic damping reduction and moment resistance decrement due to continuously reversed
loads were found to be small because bolt pretensioning minimized the pinching effect. This study showed that the hysteresis
loop of the prestressed joint can be obtained by adding the frictional hysteresis loop due to pretension force into the hysteresis
loop of the non-pre-stressed joint. Despite a great increase of initial stiffness, only slight increments in ductility coefficient
and ultimate moment resistance were found in the prestressed joint. 相似文献
354.
Kazuhira Yokoyama Masanori Yumura Tadashi Honda Eriko Ajitomi 《Soil Science and Plant Nutrition》2016,62(3):230-239
Nitrous oxide, one of the earth-warming and ozone-destructing gases, is produced through either nitrification or denitrification depending on the O2 availability in soil. Aerobically denitrifying bacteria express denitrification tract even under the gas phase containing O2 at the ambient air level. The net reduction of exogenous N2O by novel aerobically denitrifying bacteria were studied. We carried out two different isolation strategies in the primary screening. One was to select isolates of interest out of periplasmic nitrate reductase-dependent denitrifying bacteria in a eutrophic condition. The other was to use diluted nutrient agar to allow the formation of colonies of diverse bacteria. Among aerobically denitrifying bacteria, those which showed net aerobic N2O reduction were only minor populations. As a result, eight isolates belonging to Proteobacteria were obtained from soil and cow manure. The denitrification and net N2O reduction properties of the three representative isolates, Pseudomonas sp. CM1, Thauera sp. PM2 and Paracoccus denitrificans 96, were determined separately by the acetylene inhibition method after exposure to aerobic or low O2 conditions, a 24 h starvation prior to the determination of the aerobic activity and inoculation to a cow manure-amended sterile soil. The phenotype inversion from net N2O-reducing to N2O-emitting, and vice versa, attested to the fact that activity of the N2O-producing and -reducing steps changed in different intensities to each other. The activity values and the direction of activity changes varied among the isolates. When they were inoculated in a sterilized soil microcosm at 40% maximum water holding capacity, the denitrification and the N2O-reducing activities were comparable with or, in some cases, facilitated more than those determined under the low-O2 condition. It is possible that these isolates sensed the O2 deficiency even in such a relatively dry condition. Pseudomonas sp. CM1 was unique because it lacked nitrate reducing activity and acted as a net aerobic N2O reducer. 相似文献
355.
Toshihiro Wada Kyoichi Kamiyama Shinya Shimamura Osamu Murakami Tadashi Misaka Masayoshi Sasaki Takaaki Kayaba 《Fisheries Science》2014,80(6):1169-1179
Commercial landings of a rare pleuronectid flatfish, barfin flounder Verasper moseri, recovered drastically after large-scale stock enhancement in Hokkaido conducted since 2006. This study investigated commercial landings, fishing grounds, size distributions, and sex and age compositions of barfin flounder during 2007–2011 in southern Tohoku, their major spawning ground, which is over 700 km south of Hokkaido. Landings, mostly comprising stocked fish, increased drastically in southern Tohoku: from 2.0 tons in 2007 to 20.8 tons in 2010. Over 98 % of them were landed during January–April, with the peak period during February–March. Fishing logbook data of offshore bottom-trawl vessels during 2007–2010 revealed the upper continental slope off southernmost Tohoku as the main fishing ground (35°40′–36°50′N, annual weighted mean depth 267–299 m). Two size modes in the landings consisted of males (ca. 40 cm) and females (ca. 60 cm). The main age at fishery recruitment in southern Tohoku was younger for males (age 2+) than for females (ages 3+ and 4+), the result of which was that the female percentage was lowest at 1.5 % in 2009 and highest at 7.9 % in 2011. Our results showed clearly how the effectiveness of large-scale stock enhancement in Hokkaido extended to southern Tohoku in association with spawning migration of stocked barfin flounder. 相似文献
356.
Brassinosteroid(BR) and gibberellin(GA) are two predominant plant hormones that regulate plant cell elongation. Mutants disrupt the biosynthesis of these hormones and display different degrees of dwarf phenotypes in rice. Although the role of each plant hormone in promoting the longitudinal growth of plants has been extensively studied using genetic methods, their relationship is still poorly understood. In this study, we used two specific inhibitors targeting BR and GA biosynthesis to investigate the roles of BR and GA in growth of rice seedlings. Yucaizol, a specific inhibitor of BR biosynthesis, and Trinexapac-ethyl, a commercially available inhibitor of GA biosynthesis, were used. The effect of Yucaizol on rice seedlings indicated that Yucaizol significantly retarded stem elongation. The IC_(50) value was found to be approximately 0.8 μmol/L. Yucaizol also induced small leaf angle phenocopy in rice seedlings, similarly to BR-deficient rice, while Trinexapac-ethyl did not. When Yucaizol combined with Trinexapac-ethyl was applied to the rice plants, the mixture of these two inhibitors retarded stem elongation of rice at lower doses. Our results suggest that the use of a BR biosynthesis inhibitor combined with a GA biosynthesis inhibitor may be useful in the development of new technologies for controlling rice plant height. 相似文献
357.
358.
Tenta Segawa Chisato Nishiyama Muluneh Tamiru-Oli Yu Sugihara Akira Abe Hinako Sone Noriaki Itoh Mayu Asukai Aiko Uemura Kaori Oikawa Hiroe Utsushi Ayako Ikegami-Katayama Tomohiro Imamura Masashi Mori Ryohei Terauchi Hiroki Takagi 《Breeding Science》2021,71(3):299
Advances in next generation sequencing (NGS)-based methodologies have accelerated the identifications of simple genetic variants such as point mutations and small insertions/deletions (InDels). Structural variants (SVs) including large InDels and rearrangements provide vital sources of genetic diversity for plant breeding. However, their analysis remains a challenge due to their complex nature. Consequently, novel NGS-based approaches are needed to rapidly and accurately identify SVs. Here, we present an NGS-based bulked-segregant analysis (BSA) technique called Sat-BSA (SVs associated with traits) for identifying SVs controlling traits of interest in crops. Sat-BSA targets allele frequencies at all SNP positions to first identify candidate genomic regions associated with a trait, which is then reconstructed by long reads-based local de novo assembly. Finally, the association between SVs, RNA-seq-based gene expression patterns and trait is evaluated for multiple cultivars to narrow down the candidate genes. We applied Sat-BSA to segregating F2 progeny obtained from crosses between turnip cultivars with different tuber colors and successfully isolated two genes harboring SVs that are responsible for tuber phenotypes. The current study demonstrates the utility of Sat-BSA for the identification of SVs associated with traits of interest in species with large and heterozygous genomes. 相似文献
359.
Maika Shiozawa Daisuke Shiode Junichi Okuyama Fuxiang Hu Tadashi Tokai 《水产资源保护:海洋与淡水生态系统》2019,29(12):2107-2115
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360.
Koito Tomoko Nakamura-Kusakabe Ikumi Yoshida Takao Maruyama Tadashi Omata Tamano Miyazaki Nobuyuki Inoue Koji 《Fisheries Science》2010,76(2):381-388
Seawater around deep-sea hydrothermal vents and cold seeps contain high levels of hydrogen sulfide, which is toxic to most
animals. Invertebrates inhabiting these environments have been reported to accumulate high levels of thiotaurine, a sulfur-containing
amino acid. Thiotaurine is likely to play an important role in sulfide detoxification, but its functions in the detoxification
process are still unknown. We cloned methane-seep mussel Bathymodiolus platifrons cDNA encoding the taurine transporter (TAUT), which transports thiotaurine and its precursors across the cell membrane. Phylogenetic
analyses revealed that the predicted peptide formed a clade with the TAUTs of shallow-water mussel Mytilus galloprovincialis and the hydrothermal vent mussel Bathymodiolus septemdierum that harbors thioautotrophic bacteria. We then reared B. platifrons in the presence or absence of Na2S and quantified TAUT mRNA using a real-time PCR system. The amount of TAUT mRNA in the gills of B. platifrons increased with rearing in the presence of Na2S for 69 days, but no change was observed in the absence of sulfide. These results suggest that TAUT plays an important role
in sulfide detoxification, even in species that do not harbor thioautotrophic bacteria. The TAUT mRNA level was variable in
the mantle and low in the foot throughout the entire rearing period, regardless of the presence/absence of sulfide, suggesting
that TAUT gene expression is regulated differentially in each tissue. 相似文献